Historically, television services have been comprised of analog broadcast audio and video signals. Cable television systems now receive broadcasts and retransmit them with other programming to users over land-line networks, typically comprising fiber optic cable and/or coaxial cable. With the recent advent of digital transmission technology, cable television systems are now capable of providing much more than the traditional analog broadcast video. For instance, two-way and advanced one-way communications between a subscriber and a cable system headend are now possible.
In implementing enhanced programming, the home communication terminal (“HCT”), otherwise known as the set top box, has become an important computing device for accessing video services and navigating a subscriber through a maze of available services. In addition to supporting traditional analog broadcast video functionality, digital HCTs (or “DHCTs”) now also support an increasing number of services which employ digital two-way communications, such as video-on-demand, email and web-browsing. These are all in addition to the host of other television services which are increasingly being demanded by consumers, examples of which include audio and audio/visual programming, advanced navigation controls, impulse pay-per-view technology, and on-line commerce.
With the addition of interactive services and the increased bandwidth and the emergence of bi-directional communication capabilities available through a digital television system, there is a need to provide subscribers new methods of controlling DHCT capabilities and accessing the channels and/or services with relative ease. Currently, controlling the DHCT to access these services requires familiarization and use of input devices such as an infrared wireless remote control or a wired or wireless keyboard. Conventional remote control systems for audio and video equipment normally comprise a battery-powered, handheld, transmitter which encodes and transmits selected keyboard information and generates the necessary control signals for operating the selected functions of the user's equipment. Most such systems employ a transmission system operable in the infrared region of the spectrum for transmitting the control data. Such a device allows one to operate the equipment from a distance, without connecting wires. The drawback with such communication equipment is that subscribers need to familiarize themselves with increasingly complicated remote control devices to control and select the myriad of services and programming available. Furthermore, as operators of cable television systems continue to add services and applications, problems also exist in both making the subscriber aware of and also in providing quick access to the new services and channels.
Voice activated remote controls for controlling televisions, video cassette recorders, stereo equipment, and cable and satellite receivers are well known. There, voice activated remotes typically recognize a limited number of voice commands from a limited number of users. Using the voice activated remote, users can select a hands free or manual operation mode. The device performs speech recognition and associated DSP processing in the remote control device, and transmits signals representing the function to the device to which it controls. However, a drawback with such a device is that it is limited in the number of commands that may be processed, and by the number of users that can use the device.
In one embodiment, transport stream output by multiplexer 910 may undergo adaptation to a network layer such internet protocol (IP) at the DSP 904 or multiplexer 910 prior to error correction and modulation 912 wherein the error correction and modulation 912 is performed to fulfill the physical layer in part. Furthermore, packets output by network layer adaptation may further undergo adaptation to a link layer, such as Ethernet, for framing.